4.a.2. Overall Objective The overall objective of the Imaging Core is to provide MRDDRC investigators access to state-of-theart microscopic imaging and the capacity for three-dimensional reconstructions of neural preparations. Over the past five years, new imaging systems have been added to the already substantial capabilities of the Core. The three-dimensional image reconstruction system that has been the center of the Core for two decades now is based on affordable personal computer platforms, allowing individual laboratories to import and export images to their own desktops as well as to work on the computers within the Imaging Core. The confocal microscopes and digital imaging microscopes add powerful image acquisition and analysis capabilities. Moreover, image files generated by these microscopes can be easily formatted to be compatible with such standard image programs as Adobe Photoshop running on desktop PC or Macintosh computers. By adopting standard image formats and "point-and-click" Windows/Maclntosh/Xwindows computer interfaces, the Core has been designed for ease of use and maximum flexibility. Moreover and importantly, the Core Director and System Manager are available for individualized instruction in the use of the Core, and training workshops have been conducted as new imaging systems have been added. This training objective is a critical aspect of the Core's function and the MRDDRC mission.